The development of biomineralization in seafloor extreme environment (including hydrothermal vent and cold seeping systems) is conducive to the research and the exploration about the early earth’s history, the life evolution, the subsurface biosphere and the terrestrial planets. The hydrothermal biomineralization has in the decade becomes the focus of geobiological research with the introduction of the microelectronic technology and molecular biology technology. Available information indicates that microorganisms play a critical role in the formations of Fe-Si oxyhydroxide and silicate deposits in the hydrothermal systems globally. Furthermore,the seafloorcold seeping is also tantalizing to every marine scientist. Voluminoushydrocarbon-rich fluids are transferred into seawater or even atmosphere via pervasive seafloor cold seepage systems, where a series of important biogeochemical processes occur and sustain a broad diversity of ecosystems, relying on the energy derived by chemosynthetic microbes from the oxidation of reduced chemical compounds. Both of these extreme systems are our current research interests. The involved study areas include the Southwest Indian Ridge, the Lau back arc basin, and the Okinawa Trough in the Pacific.